This is a book about the unity of the church of Christ, and chapter 1 is a short theology of the unity of the church. This unity is a demonstration of God’s purpose of cosmic unity. The church further displays the unity and uniqueness of God. The gift of unity is on the one hand a mark of the church and on the other hand to be pursued without ceasing. Texts that receive due attention are Ephesians 2:13-16, Ephesians 3:8-11, and Ephesians 4:1-13.